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<ul id="index">
  <li><a href="#NAME">NAME</a></li>
  <li><a href="#SYNOPSIS">SYNOPSIS</a></li>
  <li><a href="#DESCRIPTION">DESCRIPTION</a></li>
  <li><a href="#RETURN-VALUES">RETURN VALUES</a></li>
  <li><a href="#EXAMPLES">EXAMPLES</a></li>
  <li><a href="#SEE-ALSO">SEE ALSO</a></li>
  <li><a href="#HISTORY">HISTORY</a></li>
  <li><a href="#COPYRIGHT">COPYRIGHT</a></li>
</ul>

<h1 id="NAME">NAME</h1>

<p>OSSL_ENCODER_to_data, OSSL_ENCODER_to_bio, OSSL_ENCODER_to_fp - Routines to perform an encoding</p>

<h1 id="SYNOPSIS">SYNOPSIS</h1>

<pre><code>#include &lt;openssl/encoder.h&gt;

int OSSL_ENCODER_to_data(OSSL_ENCODER_CTX *ctx, unsigned char **pdata,
                         size_t *pdata_len);
int OSSL_ENCODER_to_bio(OSSL_ENCODER_CTX *ctx, BIO *out);
int OSSL_ENCODER_to_fp(OSSL_ENCODER_CTX *ctx, FILE *fp);</code></pre>

<p>Feature availability macros:</p>

<dl>

<dt id="OSSL_ENCODER_to_fp-is-only-available-when-OPENSSL_NO_STDIO-is-undefined">OSSL_ENCODER_to_fp() is only available when <b>OPENSSL_NO_STDIO</b> is undefined.</dt>
<dd>

</dd>
</dl>

<h1 id="DESCRIPTION">DESCRIPTION</h1>

<p>OSSL_ENCODER_to_data() runs the encoding process for the context <i>ctx</i>, with the output going to the <i>*pdata</i> and <i>*pdata_len</i>. If <i>*pdata</i> is NULL when OSSL_ENCODER_to_data() is called, a buffer will be allocated using <a href="../man3/OPENSSL_zalloc.html">OPENSSL_zalloc(3)</a>, and <i>*pdata</i> will be set to point at the start of that buffer, and <i>*pdata_len</i> will be assigned its length when OSSL_ENCODER_to_data() returns. If <i>*pdata</i> is non-NULL when OSSL_ENCODER_to_data() is called, <i>*pdata_len</i> is assumed to have its size. In this case, <i>*pdata</i> will be set to point after the encoded bytes, and <i>*pdata_len</i> will be assigned the number of remaining bytes.</p>

<p>OSSL_ENCODER_to_bio() runs the encoding process for the context <i>ctx</i>, with the output going to the <b>BIO</b> <i>out</i>.</p>

<p>OSSL_ENCODER_to_fp() does the same thing as OSSL_ENCODER_to_bio(), except that the output is going to the <b>FILE</b> <i>fp</i>.</p>

<p>For OSSL_ENCODER_to_bio() and OSSL_ENCODER_to_fp(), the application is required to set up the <b>BIO</b> or <b>FILE</b> properly, for example to have it in text or binary mode as is appropriate for the encoder output type.</p>

<h1 id="RETURN-VALUES">RETURN VALUES</h1>

<p>OSSL_ENCODER_to_bio(), OSSL_ENCODER_to_fp() and OSSL_ENCODER_to_data() return 1 on success, or 0 on failure.</p>

<h1 id="EXAMPLES">EXAMPLES</h1>

<p>To encode a pkey as PKCS#8 with PEM format into a bio:</p>

<pre><code>OSSL_ENCODER_CTX *ectx;
const char *format = &quot;PEM&quot;;
const char *structure = &quot;PrivateKeyInfo&quot;; /* PKCS#8 structure */
const unsigned char *pass = &quot;my password&quot;;

ectx = OSSL_ENCODER_CTX_new_for_pkey(pkey,
                                     OSSL_KEYMGMT_SELECT_KEYPAIR
                                     | OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS,
                                     format, structure,
                                     NULL);
if (ectx == NULL) {
    /* error: no suitable potential encoders found */
}
if (pass != NULL)
    OSSL_ENCODER_CTX_set_passphrase(ectx, pass, strlen(pass));
if (OSSL_ENCODER_to_bio(ectx, bio)) {
    /* pkey was successfully encoded into the bio */
} else {
    /* encoding failure */
}
OSSL_ENCODER_CTX_free(ectx);</code></pre>

<p>To encode a pkey as PKCS#8 with DER format encrypted with AES-256-CBC into a buffer:</p>

<pre><code>OSSL_ENCODER_CTX *ectx;
const char *format = &quot;DER&quot;;
const char *structure = &quot;PrivateKeyInfo&quot;; /* PKCS#8 structure */
const unsigned char *pass = &quot;my password&quot;;
unsigned char *data = NULL;
size_t datalen;

ectx = OSSL_ENCODER_CTX_new_for_pkey(pkey,
                                     OSSL_KEYMGMT_SELECT_KEYPAIR
                                     | OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS,
                                     format, structure,
                                     NULL);
if (ectx == NULL) {
    /* error: no suitable potential encoders found */
}
if (pass != NULL) {
    OSSL_ENCODER_CTX_set_passphrase(ectx, pass, strlen(pass));
    OSSL_ENCODER_CTX_set_cipher(ctx, &quot;AES-256-CBC&quot;, NULL);
}
if (OSSL_ENCODER_to_data(ectx, &amp;data, &amp;datalen)) {
    /*
     * pkey was successfully encoded into a newly allocated
     * data buffer
     */
} else {
    /* encoding failure */
}
OSSL_ENCODER_CTX_free(ectx);</code></pre>

<h1 id="SEE-ALSO">SEE ALSO</h1>

<p><a href="../man7/provider.html">provider(7)</a>, <a href="../man3/OSSL_ENCODER_CTX.html">OSSL_ENCODER_CTX(3)</a></p>

<h1 id="HISTORY">HISTORY</h1>

<p>The functions described here were added in OpenSSL 3.0.</p>

<h1 id="COPYRIGHT">COPYRIGHT</h1>

<p>Copyright 2019-2021 The OpenSSL Project Authors. All Rights Reserved.</p>

<p>Licensed under the Apache License 2.0 (the &quot;License&quot;). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at <a href="https://www.openssl.org/source/license.html">https://www.openssl.org/source/license.html</a>.</p>


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